Nonmelanoma skin cancer is the most common cancer in the United States, with an estimated annual incidence of more than 1,000,000 cases. Basal cell carcinomas (BCC) account for 70 to 80% of nonmelanoma skin cancers. Squamous cell carcinoma (SCC), while representing only about 20% of nonmelanoma skin cancers, are significant because of their ability to metastasize and accounts for over 2300 deaths annually. The incidence of nonmelanoma skin cancer continues to increase. Early diagnosis can be lifesaving and it is important that physicians know what treatment modalities will be the most effective.
Nonmelanoma skin cancers may be treated using various procedures that excise or kill the cancerous cells. Removal of the entire tumor is essential to prevent tumor recurrence and, in some cases, metastasis. However, the clinically visible portion of a lesion may represent only a fraction of the total lesion, making excision of the entire lesion difficult. Currently, even with a precise preoperative diagnosis, complete excision of nonmelanoma skin cancer is not always achieved. Incomplete excision of these carcinomas requires further treatment such as, for example, a second excision procedure to remove the residual tumor. Thus, improved methods of diagnosis that identify the complete margins of such lesions are needed.